A drag reducing agent is one that substantially reduces the friction loss that results from the turbulent flow of a fluid. Where fluids are transported over long distances, such as in oil and other hydrocarbon liquid pipelines, these friction losses result in inefficiencies that increase equipment and operations costs. Ultra-high molecular weight polymers are known to function well as drag reducing agents, particularly in hydrocarbon liquids. In general, drag reduction depends in part upon the molecular weight of the polymer additive and its ability to dissolve in the hydrocarbon under turbulent flow. Effective drag reducing polymers typically have ultra-high molecular weights in excess of five million.
One way to introduce the drag reducing polymers into the flowing hydrocarbon stream is by pumping of a drag reducing polymer suspension into the hydrocarbon stream. The ultra-high molecular weight polymers are suspended in a liquid that will not dissolve or will only partially dissolve the ultra-high molecular weight polymer. This suspension is then introduced into the flowing hydrocarbon stream. Inclusion of a partitioning agent is generally desirable in these suspensions as the drag reducing polymers, due to their soft and tacky nature, tend to agglomerate, or “cold flow”, when their unaltered surfaces come into contact with one another. Conventional partitioning agents, such as fatty waxes, often have limited solubility, particularly in cold hydrocarbon fluids, such as cold refined hydrocarbon fluids, for example diesel. As a result, frequent filter plugging issues result owing to undissolved partitioning agent.
It would be desirable, then, to provide a drag reducing composition containing a partitioning agent having increased solubility, especially in cold hydrocarbon fluids.